CN107643138A - Miniature steel-pipe pile body stress test device - Google Patents
Miniature steel-pipe pile body stress test device Download PDFInfo
- Publication number
- CN107643138A CN107643138A CN201710938330.9A CN201710938330A CN107643138A CN 107643138 A CN107643138 A CN 107643138A CN 201710938330 A CN201710938330 A CN 201710938330A CN 107643138 A CN107643138 A CN 107643138A
- Authority
- CN
- China
- Prior art keywords
- steel pipe
- pipe pile
- miniature steel
- compensation type
- temperature self
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 238000012360 testing method Methods 0.000 title claims abstract description 39
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 146
- 239000010959 steel Substances 0.000 claims abstract description 146
- 239000013307 optical fiber Substances 0.000 claims abstract description 120
- 239000000835 fiber Substances 0.000 claims abstract description 38
- 238000013500 data storage Methods 0.000 claims abstract description 21
- 230000004083 survival effect Effects 0.000 claims abstract description 15
- 238000007569 slipcasting Methods 0.000 claims description 30
- 238000005452 bending Methods 0.000 claims description 27
- 239000011083 cement mortar Substances 0.000 claims description 18
- 238000009412 basement excavation Methods 0.000 claims description 15
- 238000010276 construction Methods 0.000 claims description 13
- 238000009434 installation Methods 0.000 claims description 12
- 230000000694 effects Effects 0.000 claims description 11
- 238000013461 design Methods 0.000 claims description 10
- 238000000034 method Methods 0.000 claims description 10
- 238000003466 welding Methods 0.000 claims description 7
- 238000006073 displacement reaction Methods 0.000 claims description 5
- 238000005553 drilling Methods 0.000 claims description 5
- 239000003795 chemical substances by application Substances 0.000 claims description 4
- 230000006835 compression Effects 0.000 claims description 4
- 238000007906 compression Methods 0.000 claims description 4
- 239000002002 slurry Substances 0.000 claims description 4
- 244000137852 Petrea volubilis Species 0.000 claims description 3
- 238000004140 cleaning Methods 0.000 claims description 3
- 238000001816 cooling Methods 0.000 claims description 3
- 238000001514 detection method Methods 0.000 claims description 3
- 238000000605 extraction Methods 0.000 claims description 3
- 239000002689 soil Substances 0.000 claims description 3
- 238000009835 boiling Methods 0.000 claims description 2
- 230000007423 decrease Effects 0.000 claims 1
- 230000035945 sensitivity Effects 0.000 abstract description 5
- 238000005259 measurement Methods 0.000 abstract description 4
- 238000005520 cutting process Methods 0.000 abstract description 3
- 238000011065 in-situ storage Methods 0.000 abstract description 3
- 238000012544 monitoring process Methods 0.000 abstract description 3
- 229920001410 Microfiber Polymers 0.000 abstract 2
- 239000003658 microfiber Substances 0.000 abstract 2
- 238000009662 stress testing Methods 0.000 abstract 1
- 238000005516 engineering process Methods 0.000 description 7
- 238000009826 distribution Methods 0.000 description 6
- 230000003287 optical effect Effects 0.000 description 5
- 239000011513 prestressed concrete Substances 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 230000005672 electromagnetic field Effects 0.000 description 2
- 229940085805 fiberall Drugs 0.000 description 2
- 239000011888 foil Substances 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 1
- 210000004556 brain Anatomy 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- 238000002513 implantation Methods 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 230000002787 reinforcement Effects 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
Landscapes
- Length Measuring Devices By Optical Means (AREA)
- Piles And Underground Anchors (AREA)
Abstract
The invention belongs to the technical field of geotechnical engineering in-situ test equipment, and particularly relates to a miniature steel pipe pile body stress testing device.A pile end part of a miniature steel pipe pile is welded into a closed pointed shape; the sensor mounting holes are formed in a flame cutting mode, clamping blocks are arranged at two ends of the temperature self-compensation type micro fiber bragg grating strain sensor and are welded on the micro steel pipe pile, and optical fibers among the temperature self-compensation type micro fiber bragg grating strain sensors and optical fibers led out of the bottom surface are protected by armored wires; the hole cutting plate is welded on the surface of the miniature steel pipe pile and completely covers the sensor mounting hole, the wire end of the temperature self-compensation type miniature fiber grating strain sensor string is led out through the lead hole and is connected with the fiber grating sensing analyzer, the fiber grating sensing analyzer is connected with the data storage computer, and the temperature self-compensation type miniature fiber grating strain sensor string is simple in structure device, high in measurement precision, high in sensitivity, small in error, strong in anti-electromagnetic field interference capacity, high in survival rate and easy to realize quasi-distributed and automatic monitoring.
Description
Technical field：
It is micro- in more particularly to a kind of foundation ditch or slope retaining the invention belongs to rock-soil engineering in-situ technical field of test equipment
Shaped steel pile tube stress test device, make up and improve the deficiency of current test device and method of testing, by along miniature steel pipe
Stake pile body, which buries self-compensation type mini optical fibre grating strain transducer string, more accurately to draw miniature steel pipe pile in Water And Earth Pressures
The pile body bending stress regularity of distribution under effect, certain reference price is provided for later more in-depth study and Practical Project
Value.
Background technology：
Mini pile is a kind of Small Diameter Pile to be grown up based on root pile, and stake footpath is generally 90~300mm.It is and micro-
Shaped steel pile tube refers to use a kind of mini pile of the steel pipe as intensive aspect.Because miniature steel pipe pile has, ground adaptability is strong, holds
Load power is high, arrangement form is more flexible, construction occupied ground is small, in light weight, pore-forming is fast, construction machinery is minimized and can surpassed
Many advantages, such as preceding supporting, it is used widely in recent years in the engineering such as pattern foundation pit supporting structure and slope reinforcement, particularly in Tu Yan
Coordinate anchor pole (rope) to use in compound stratum, form a kind of New Supporting pattern.In Excavation Process, miniature steel pipe pile exists
Water And Earth Pressures effect under occur bending and deformation, larger bending stress will be produced, for effectively checking miniature steel pipe pile by masterpiece
With, guarantee construction safety and construction quality, and provide data for design, it is necessary to miniature steel pipe pile in Excavation Process
Bending stress is monitored in real time, it is ensured that steel-pipe pile stress meets safety requirements.Traditional electric detecting technology is mostly using in pile body
The method that outer wall pastes foil gauge, test result is protected from environmental larger, and actual loading result exists certain with test result
Error, and the survival rate of disturbing influence foil gauge mechanical in by site operation vibrations and digging process is not high, causes to test number
According to missing.Fiber grating sensing technology is accompanied by the development of Fibre Optical Communication Technology and fibre optics and a kind of caused new light
Electronics technologies, fiber Bragg grating strain sensor can be sensed extraneous trickle strain by the movement of bragg reflection wavelength and become
Change, be a kind of sensing element of function admirable so as to realize on-line measurement structural stress, compared with traditional electric detecting technology, tool
There are good stability, corrosion-resistant, electromagnetism interference, quasi- distribution measuring, small volume, simple in construction, precision is high, can be supervised in real time
The features such as survey.Because optical fiber is very thin and weak, careful installation, Fibre Optical Sensor prison in situ must be carried out to sensor and Transmission Fibers
How at the scene the key for surveying success or failure is realizing the embedded positioning of sensor in construction environment and is ensureing its survival rate.It is Chinese special
Profit 201320628409.9 discloses a kind of static pressure high-strength prestressed concrete pipe pile pile stress test device, high-strength prestressed
Concrete tubular pile internal cutting is formed with shallow slot, optical fiber Bragg grating sensor and armored optical cable and connected by quasi-distributed welding, series connection
Optical fiber Bragg grating sensor and armored optical cable implantation high-strength prestressed concrete pipe pile shallow slot in and mixed with epoxy resin
Close liquid and be packaged protection, optical fiber Bragg grating sensor is tested as needed in the position of high-strength prestressed concrete pipe pile
Soil layer absolute altitude laid；The inside top of high-strength prestressed concrete pipe pile, which is opened, is formed with pile body drilling, and armored optical cable passes through
Pile body drilling is drawn to be connected with data collecting system；Its apparatus structure is simple, easy to operate, and measurement accuracy is high, high sensitivity, resists
Interference of electromagnetic field ability is strong, and survival rate is high, quasi-distributed and automatic monitoring is easily achieved compared with traditional load-sensing unit, still
The test device is mainly for the PHC piles in soft stratum, embedding optical fibre Bragg grating sensing
Device string once has a failure to cause large effect to test process, or even sensor string can be caused all to fail；In addition
Pile body fluting can affect to the intensity of stake, furthermore fail to reject the pile strain as caused by temperature in test process
Change is so that influence the accuracy of test result.
The content of the invention：
The shortcomings that it is an object of the invention to overcome prior art to exist, seek one kind can measure accurately, in real time it is miniature
The device of steel-pipe pile pile body stress, when self-compensation type mini optical fibre grating strain transducer under tension or pressure effect,
The elongation or compression of sensor make the fiber grating cycle change, and then change effective refraction of fiber Bragg grating strain sensor
Rate, so as to obtain bending stress distribution of the miniature steel pipe pile under Water And Earth Pressures effect.
To achieve these goals, the agent structure of miniature steel pipe pile pile stress test device of the present invention includes micro-
Shaped steel pile tube, temperature self-compensation type mini optical fibre grating strain transducer string, sheathed wire, optical fiber grating sensing analyzer, number
According to storage computer, sensor mounting hole, hole excision plate and fairlead；Miniature steel pipe pile uses the commercially available steel commonly used in engineering
Pipe, it is pointed that stake end is welded into closing；Sensor mounting hole is in a manner of gas flame cuttiug in miniature steel pipe pile pore-forming, sensor installation
Hole is 4cm × 7cm square-section, and its long side is consistent with the axis direction of miniature steel pipe pile, and the centre of form of sensor mounting hole is cut
Face overlaps with the centre of form section of each temperature self-compensation type mini optical fibre grating strain transducer；The miniature light of temperature self-compensation type
The standard that fiber grating strain transducer string is connected into by temperature self-compensation type mini optical fibre grating strain transducer according to design requirement
Distributed sensor string, temperature self-compensation type mini optical fibre grating strain transducer string are arranged in miniature steel pipe in a welding manner
The inner surface of stake, the number of temperature self-compensation type mini optical fibre grating strain transducer is according to being actually needed determination, each temperature
There is grip block at self-compensation type mini optical fibre grating strain transducer both ends, and grip block is welded on miniature steel pipe pile, wherein each temperature
The optical fiber of optical fiber and extraction bottom surface between degree self-compensation type mini optical fibre grating strain sensing is all protected with sheathed wire；
Sensor mounting hole on miniature steel pipe pile surface and is completely covered by by hole excision plate weld, temperature self-compensation type mini optical fibre light
The end of a thread of grid strain transducer string is drawn by the fairlead at the top of miniature steel pipe pile and is connected with optical fiber grating sensing analyzer,
Optical fiber grating sensing analyzer is connected with data storage computer, during whole Installation And Test, it is ensured that sheathed wire it is curved
Knuckle degree is not more than 90 degree, in order to avoid optical fiber fractures, temperature self-compensation type fiber Bragg grating strain sensor being capable of automatic rejection temperature
Change the influence to test result.
The present invention complete stress test specific embodiment be：
(1) according to the design requirement of miniature steel pipe pile section to be measured, determine that temperature self-compensation type mini optical fibre grating should
Become the spacing of each sensor in sensor string, temperature self-compensation type mini optical fibre grating strain transducer is connected into quasi-distributed
Temperature self-compensation type mini optical fibre grating strain transducer string, between each temperature self-compensation type mini optical fibre grating strain sensing
Optical fiber and draw bottom surface optical fiber all protected with sheathed wire；
(2) temperature self-compensation type mini optical fibre grating strain transducer string first connects light before miniature steel pipe pile installation
Fine grating sensing analyzer and data storage computer, on the one hand check whether optical fiber fractures, on the other hand examine temperature self-compensation
Whether the type fiber Bragg grating strain sensor of declining fails；
(3) installation site according to temperature self-compensation type mini optical fibre grating strain transducer string in miniature steel pipe pile,
Position and the size of sensor mounting hole are drawn with chalk in miniature steel pipe pile outer wall, in miniature steel pipe in a manner of gas flame cuttiug
Stake pore-forming, the centre of form section of sensor mounting hole are tried one's best and each temperature self-compensation type mini optical fibre grating strain transducer
Centre of form section is overlapped, and after miniature steel pipe pile cooling, the miniature light of temperature self-compensation type is installed to miniature steel pipe pile inwall with sand paper
Polished the position of fiber grating strain transducer string；
(4) by two string temperature self-compensation type mini optical fibre grating sensor strings from the end of miniature steel pipe pile along enter miniature steel
The inside of pile tube, two string temperature self-compensation type mini optical fibre grating strain transducer strings are symmetrically welded by sensor mounting hole
In the inwall of miniature steel pipe pile, optical fiber grating sensing analyzer and data storage computer are connected after the completion of welding, examines temperature certainly
The survival rate of compensation fiber Bragg grating strain sensor string makes it to be less than 90%, if temperature self-compensation type fiber grating strain
The survival rate of sensor string is less than 90%, it is necessary to the sensor for removing damage is reinstalled, and cuts hole after having inspected
Except sensor mounting hole is completely covered by miniature steel pipe pile surface by plate weld, it is ensured that weldquality, temperature self-compensation type are miniature
Fiber Bragg grating strain sensor string the end of a thread (each temperature self-compensation type mini optical fibre grating strain transducer string the end of a thread, one
Damaged on end can badly be tested by the other end) drawn by the fairlead at the top of miniature steel pipe pile；
(5) construction part of miniature steel pipe pile is determined on construction ground, and using down-the-hole pore-forming, borehole cleaning, aperture is slightly larger than micro-
The diameter of shaped steel pile tube；Miniature steel pipe pile with temperature self-compensation type mini optical fibre grating strain transducer string is put into and is drilled
Hole in, it is ensured that wherein a string of temperature self-compensation type mini optical fibre grating strain transducer displacements are another in excavation of foundation pit face
Displacement is in facing native face, if miniature steel pipe pile can not lean on its deadweight to be put into drilling, using Miniature digging machine by miniature steel pipe pile gently
Predetermined absolute altitude is squeezed into, it is noted that protection temperature self-compensation type mini optical fibre grating strain passes in miniature steel pipe pile work progress
Sensor string and the ring flange of sheathed wire termination；
(6) Grouting Pipe is inserted to the bottom of miniature steel pipe pile, the cement mortar mixed slowly injected by slip casting machine miniature
In steel-pipe pile, the ratio of mud of cement mortar is strict controlled in 0.45~0.5, to pay attention to the pressure in Grouting Pipe during slip casting the moment
Table, it is ensured that grouting pressure reaches 0.5MPa, and Grouting Pipe wouldn't be pulled out after slip casting, until cement mortar flows out outside miniature steel pipe pile and is
Only, Grouting Pipe is extracted, sealed steel pipe end, is pressurizeed 5 minutes, untill treating that cement mortar flows out outside steel pipe again, if once grouting
Be difficult to meet set rushing be full of coefficient requirement, it is necessary to repeatedly gap slip casting, until untill the frost boiling of miniature steel pipe pile stake top, then
Grouting Pipe is extracted, completes slip casting operation, the ring flange of sheathed wire termination is ensured during slip casting slurries entrance；
(7) by temperature self-compensation type fiber Bragg grating strain sensor string, optical fiber grating sensing analyzer and data storage electricity
Brain is connected, the survival rate of detection temperature self-compensation type mini optical fibre grating strain transducer string；
(8) before excavation of foundation pit, the cement mortar in the miniature steel pipe pile after slip casting conserves 28 days or the resistance to compression of cement mortar
After intensity reaches the 75% of design strength, temperature self-compensation type fiber Bragg grating strain sensor string, optical fiber grating sensing are analyzed
Instrument and data storage computer are connected, and check whether test device connection is intact, and record temperature self-compensation type fiber grating strain
Sensor string initial wavelength；
(9) in Excavation Process, it is self-complementary that temperature is recorded in real time with optical fiber grating sensing analyzer and data storage computer
The wavelength for the type fiber-optic grating sensor string that declines is repaid, the to be measured of miniature steel pipe pile can be tried to achieve using formula (1), (2), (3)
The pile body bending stress of section,
Δεx=Δ λε/Kε (1)
σi=EsΔεx (2)
Mi=σiW (3)
Wherein Δ εxFor the axial strain variable quantity of miniature steel pipe pile；ΔλεCentered on wavelength variable quantity, unit nm；KεFor
Strain transducer sensitivity coefficient；σiFor the bending stress at any test section mini steel-pipe pile axis, its numerical value is equal to foundation ditch
Face the half in native face and excavation face stress difference, units MPa；EsFor the modulus of elasticity of miniature steel pipe pile, units MPa；MiTo be any
Test the moment of flexure of section mini steel-pipe pile, unit kNm；W be miniature steel pipe pile bending sections coefficient, unit mm3；For peace
Full consideration, formula (3) do not consider increase effect of the slip casting to bending rigidity in miniature steel pipe pile in calculated bending moment；If
The increase effect of miniature steel pipe pile bending rigidity, can be multiplied by 1.2~1.5 by the rigidity of non-slip casting miniature steel pipe pile after consideration slip casting
Enhancement coefficient.
Of the invention its constructional device is simple compared with existing measuring technology, and measurement accuracy is high, and high sensitivity, error is small, resists
Interference of electromagnetic field ability is strong, and survival rate is high, and quasi-distributed and automatic monitoring is easily achieved compared with traditional test element.
Brief description of the drawings：
Fig. 1 is the agent structure principle schematic of miniature steel pipe pile pile stress test device of the present invention.
Fig. 2 is miniature steel pipe pile perforate schematic diagram of the present invention.
Fig. 3 is the plan structure signal of temperature self-compensation type mini optical fibre grating strain transducer string of the present invention installation
Figure.
Fig. 4 is miniature steel pipe pile bending distribution map (one) described in the embodiment of the present invention.
Fig. 5 is miniature steel pipe pile bending distribution map (two) described in the embodiment of the present invention.
Embodiment：
The invention will be further described by way of example and in conjunction with the accompanying drawings.
Embodiment：
The agent structure of miniature steel pipe pile pile stress test device described in the present embodiment includes miniature steel pipe pile 1, temperature
Self-compensation type mini optical fibre grating strain transducer string 2, sheathed wire 3, optical fiber grating sensing analyzer 4, data storage computer
5th, sensor mounting hole 6, hole excision plate 7 and fairlead 8；Miniature steel pipe pile 1 is using the commercially available steel pipe commonly used in engineering, stake
It is pointed that end is welded into closing；Sensor mounting hole 6 is in a manner of gas flame cuttiug in the pore-forming of miniature steel pipe pile 1, sensor mounting hole 6
For 4cm × 7cm square-section, its long side is consistent with the axis direction of miniature steel pipe pile 1, and the centre of form of sensor mounting hole 6 is cut
Face overlaps with the centre of form section of each temperature self-compensation type mini optical fibre grating strain transducer；The miniature light of temperature self-compensation type
The standard that fiber grating strain transducer string 2 is connected into by temperature self-compensation type mini optical fibre grating strain transducer according to design requirement
Distributed sensor string, temperature self-compensation type mini optical fibre grating strain transducer string 2 are arranged in miniature steel in a welding manner
The inner surface of pile tube 1, the number of temperature self-compensation type mini optical fibre grating strain transducer determined according to being actually needed, Mei Gewen
There is grip block at degree self-compensation type mini optical fibre grating strain transducer both ends, and grip block is welded on miniature steel pipe pile 1, wherein respectively
The optical fiber of optical fiber and extraction bottom surface between temperature self-compensation type mini optical fibre grating strain sensing is all protected with sheathed wire 3
Shield；Hole excision plate 7 is welded on the surface of miniature steel pipe pile 1 and is completely covered by sensor mounting hole 6, and temperature self-compensation type is miniature
The end of a thread of fiber Bragg grating strain sensor string 2 is drawn by the fairlead 8 at the top of miniature steel pipe pile 1 and divided with optical fiber grating sensing
Analyzer 4 is connected, and optical fiber grating sensing analyzer 4 is connected with data storage computer 5, during whole Installation And Test, it is ensured that
The bending angle of sheathed wire 3 is not more than 90 degree, in order to avoid optical fiber fractures, temperature self-compensation type fiber Bragg grating strain sensor can
Influence of the automatic rejection temperature change to test result.
The present embodiment complete stress test specific embodiment be：
(1) according to the design requirement of 1 section to be measured of miniature steel pipe pile, determine that temperature self-compensation type mini optical fibre grating should
Become the spacing of each sensor in sensor string 2, temperature self-compensation type mini optical fibre grating strain transducer is connected into quasi- distribution
The temperature self-compensation type mini optical fibre grating strain transducer string 2 of formula, each temperature self-compensation type mini optical fibre grating strain sensing
Between optical fiber and draw bottom surface optical fiber all protected with sheathed wire 3；
(2) temperature self-compensation type mini optical fibre grating strain transducer string 2 is first connected before the installation of miniature steel pipe pile 1
Optical fiber grating sensing analyzer 4 and data storage computer 5, on the one hand check whether optical fiber fractures, on the other hand examine temperature certainly
Whether compensation mini optical fibre grating strain transducer fails；
(3) according to 2 installation position in miniature steel pipe pile 1 of temperature self-compensation type mini optical fibre grating strain transducer string
Put, position and the size of sensor mounting hole 6 are drawn with chalk in the outer wall of miniature steel pipe pile 1, micro- in a manner of gas flame cuttiug
The pore-forming of shaped steel pile tube 1, the centre of form section of sensor mounting hole 6 are tried one's best and each temperature self-compensation type mini optical fibre grating strain
The centre of form section of sensor overlaps, and after the cooling of miniature steel pipe pile 1, it is self-complementary to install temperature to the inwall of miniature steel pipe pile 1 with sand paper
Polished the position for repaying the type fiber Bragg grating strain sensor string 2 that declines；
(4) it is two string temperature self-compensation type mini optical fibre grating sensor strings 2 are miniature along entering from the end of miniature steel pipe pile 1
The inside of steel-pipe pile 1, it is by sensor mounting hole 6 that two string temperature self-compensation type mini optical fibre grating strain transducer strings 2 are right
Claim the inwall for being welded on miniature steel pipe pile 1, optical fiber grating sensing analyzer 4 and data storage computer 5, inspection are connected after the completion of welding
The survival rate (survival rate must not be less than 90%) of temperature self-compensation type fiber Bragg grating strain sensor string 2 is tested, if temperature self-compensation
The survival rate of formula fiber Bragg grating strain sensor string 2 is less than 90%, it is necessary to the sensor for removing damage is reinstalled, and examines
After the completion of hole excision plate 7 is welded on the surface of miniature steel pipe pile 1 and is completely covered by sensor mounting hole 6, it is ensured that weldquality,
The end of a thread (each temperature self-compensation type mini optical fibre grating strain of temperature self-compensation type mini optical fibre grating strain transducer string 2
2 the end of a thread of sensor string, one end damage can be tested by the other end) drawn by the fairlead 8 at the top of miniature steel pipe pile 1；
(5) construction part of miniature steel pipe pile 1 is determined on construction ground, and using down-the-hole pore-forming, borehole cleaning, aperture is slightly larger than micro-
The diameter of shaped steel pile tube 1；Miniature steel pipe pile 1 with temperature self-compensation type mini optical fibre grating strain transducer string 2 is put into
In the hole being drilled, it is ensured that wherein a string of temperature self-compensation type mini optical fibre grating strain transducer strings 2 are located at excavation of foundation pit face,
Another displacement is in facing native face, if miniature steel pipe pile 1 can not lean on its deadweight to be put into drilling, using Miniature digging machine by miniature steel pipe pile
1 gently squeezes into predetermined absolute altitude, it is noted that protection temperature self-compensation type mini optical fibre grating in the work progress of miniature steel pipe pile 1
Strain transducer string 2 and the ring flange of the termination of sheathed wire 3；
(6) Grouting Pipe is inserted to the bottom of miniature steel pipe pile 1, the cement mortar mixed slowly injected by slip casting machine miniature
In steel-pipe pile 1, the ratio of mud of cement mortar is strict controlled in 0.45~0.5, to pay attention to the pressure in Grouting Pipe during slip casting the moment
Power table, it is ensured that grouting pressure reaches 0.5MPa, and Grouting Pipe wouldn't be pulled out after slip casting, until cement mortar flows out outside miniature steel pipe pile 1
Untill, Grouting Pipe is extracted, sealed steel pipe end, is pressurizeed 5 minutes, untill treating that cement mortar flows out outside steel pipe again, ordinary circumstance,
Once grouting be difficult to meet set rushing be full of coefficient requirement, it is necessary to repeatedly gap slip casting, until the stake top of miniature steel pipe pile 1 is bursted and become muddy when a thaw sets in
Untill, Grouting Pipe is then extracted, completes slip casting operation, the ring flange of the termination of sheathed wire 3 is ensured during slip casting not have
Slurries enter；
(7) by temperature self-compensation type fiber Bragg grating strain sensor string 2, optical fiber grating sensing analyzer 4 and data storage
Computer 5 is connected, the survival rate of detection temperature self-compensation type mini optical fibre grating strain transducer string 2；
(8) before excavation of foundation pit, the cement mortar in the miniature steel pipe pile 1 after slip casting conserves 28 days or the resistance to compression of cement mortar
After intensity reaches the 75% of design strength, temperature self-compensation type fiber Bragg grating strain sensor string 2, optical fiber grating sensing are analyzed
Instrument 4 and data storage computer 5 are connected, and check whether test device connection is intact, and record temperature self-compensation type fiber grating and answer
Become the initial wavelength of sensor string 2；
(9) in Excavation Process, temperature is recorded in real time certainly with optical fiber grating sensing analyzer 4 and data storage computer 5
The wavelength of compensation mini optical fibre grating sensor string 2, miniature steel pipe pile 1 can be tried to achieve using formula (1), (2), (3)
The pile body bending stress of section to be measured,
Δεx=Δ λε/Kε (1)
σi=EsΔεx (2)
Mi=σiW (3)
Wherein Δ εxFor the axial strain variable quantity of miniature steel pipe pile；ΔλεCentered on wavelength variable quantity, unit (nm)；Kε
For strain transducer sensitivity coefficient；σiFor the bending stress at any test section mini steel-pipe pile axis, its numerical value is equal to base
Native face and the half of excavation face stress difference, unit (MPa) are faced in hole；EsFor the modulus of elasticity of miniature steel pipe pile, unit (MPa)；Mi
For the moment of flexure of any test section mini steel-pipe pile, unit (kNm)；W is the bending sections coefficient of miniature steel pipe pile, can be tabled look-up
Obtain, unit (mm3)；For the purpose of safety, formula (3) does not consider that slip casting resists in miniature steel pipe pile in calculated bending moment
The increase effect of curved rigidity；, will non-slip casting miniature steel pipe if considering the increase effect of miniature steel pipe pile bending rigidity after slip casting
The rigidity of stake is multiplied by 1.2~1.5 enhancement coefficient.
The present embodiment carries out structure such as Fig. 1 and as indicated with 2 of stress test to miniature steel pipe pile, as can be seen from Fig.,
In Excavation Process, main bearing member of the miniature steel pipe pile as supporting construction, the load born is larger, is opened in foundation ditch
The moment dug to steel-pipe pile top during substrate is maximum, and maximum respectively may be about 3.83kNm, 3.61kNm；Miniature steel pipe pile
Moment middle and upper part change greatly, bottom change it is smaller, maximal bending moment changing value appears in the top of steel-pipe pile, respectively may be about
5.15kN·m、4.42kN·m。
Claims (2)
1. a kind of miniature steel pipe pile pile stress test device, it is characterised in that agent structure includes miniature steel pipe pile, temperature certainly
Compensation mini optical fibre grating strain transducer string, sheathed wire, optical fiber grating sensing analyzer, data storage computer, sensing
Device mounting hole, hole excision plate and fairlead；Miniature steel pipe pile uses the commercially available steel pipe commonly used in engineering, and stake end is welded into envelope
Close pointed；For sensor mounting hole in miniature steel pipe pile pore-forming in a manner of gas flame cuttiug, sensor mounting hole is 4cm × 7cm's
Square-section, its long side is consistent with the axis direction of miniature steel pipe pile, centre of form section and each temperature of sensor mounting hole
The centre of form section of self-compensation type mini optical fibre grating strain transducer overlaps；Temperature self-compensation type mini optical fibre grating strain senses
The quasi-distributed sensor string that device string is connected into by temperature self-compensation type mini optical fibre grating strain transducer according to design requirement,
Temperature self-compensation type mini optical fibre grating strain transducer string is arranged in the inner surface of miniature steel pipe pile, temperature in a welding manner
The number of self-compensation type mini optical fibre grating strain transducer according to be actually needed determine, each temperature self-compensation type mini optical fibre
There is grip block at grating strain transducer both ends, and grip block is welded on miniature steel pipe pile, wherein the miniature light of each temperature self-compensation type
The optical fiber of optical fiber and extraction bottom surface between fiber grating strain sensing is all protected with sheathed wire；Hole excision plate weld exists
Sensor mounting hole is simultaneously completely covered by by miniature steel pipe pile surface, temperature self-compensation type mini optical fibre grating strain transducer string
The end of a thread is drawn by the fairlead at the top of miniature steel pipe pile and is connected with optical fiber grating sensing analyzer, optical fiber grating sensing analysis
Instrument is connected with data storage computer, during whole Installation And Test, it is ensured that and the bending angle of sheathed wire is not more than 90 degree,
In order to avoid optical fiber fractures, temperature self-compensation type fiber Bragg grating strain sensor can automatic rejection temperature change to the shadow of test result
Ring.
2. miniature steel pipe pile pile stress test device according to claim 1, it is characterised in that being completed using the device should
Power test specific embodiment be：
(1) according to the design requirement of miniature steel pipe pile section to be measured, determine that temperature self-compensation type mini optical fibre grating strain passes
The spacing of each sensor in sensor string, temperature self-compensation type mini optical fibre grating strain transducer is connected into quasi-distributed temperature
Spend self-compensation type mini optical fibre grating strain transducer string, the light between each temperature self-compensation type mini optical fibre grating strain sensing
Optical fiber that is fine and drawing bottom surface is all protected with sheathed wire；
(2) temperature self-compensation type mini optical fibre grating strain transducer string first connects optical fiber light before miniature steel pipe pile installation
Grid sense analyzer and data storage computer, on the one hand check whether optical fiber fractures, and on the other hand examine temperature self-compensation to decline
Whether type fiber Bragg grating strain sensor fails；
(3) installation site according to temperature self-compensation type mini optical fibre grating strain transducer string in miniature steel pipe pile, micro-
Shaped steel pile tube outer wall draws position and the size of sensor mounting hole with chalk, in a manner of gas flame cuttiug miniature steel pipe pile into
Hole, the centre of form that the centre of form section of sensor mounting hole is tried one's best with each temperature self-compensation type mini optical fibre grating strain transducer
Section is overlapped, and after miniature steel pipe pile cooling, temperature self-compensation type mini optical fibre light is installed to miniature steel pipe pile inwall with sand paper
Polished the position of grid strain transducer string；
(4) by two string temperature self-compensation type mini optical fibre grating sensor strings from the end of miniature steel pipe pile along enter miniature steel pipe pile
Inside, by sensor mounting hole by two string temperature self-compensation type mini optical fibre grating strain transducer strings be symmetrically welded at it is micro-
The inwall of shaped steel pile tube, optical fiber grating sensing analyzer and data storage computer are connected after the completion of welding, examine temperature self-compensation
The survival rate of formula fiber Bragg grating strain sensor string makes it to be less than 90%, if temperature self-compensation type fiber grating strain sensor
The survival rate of device string is less than 90%, it is necessary to the sensor for removing damage is reinstalled, and hole is cut off into plate after having inspected
It is welded on miniature steel pipe pile surface to be completely covered by sensor mounting hole, it is ensured that weldquality, temperature self-compensation type mini optical fibre
The end of a thread of grating strain transducer string is drawn by the fairlead at the top of miniature steel pipe pile；
(5) construction part of miniature steel pipe pile is determined on construction ground, and using down-the-hole pore-forming, borehole cleaning, aperture is slightly larger than miniature steel
The diameter of pile tube；Miniature steel pipe pile with temperature self-compensation type mini optical fibre grating strain transducer string is put into the hole being drilled
It is interior, it is ensured that wherein a string of temperature self-compensation type mini optical fibre grating strain transducer displacements are in excavation of foundation pit face, another displacement
In facing native face, if miniature steel pipe pile can not lean on its deadweight to be put into drilling, miniature steel pipe pile is gently squeezed into using Miniature digging machine
Predetermined absolute altitude, it is noted that protection temperature self-compensation type mini optical fibre grating strain transducer in miniature steel pipe pile work progress
String and the ring flange of sheathed wire termination；
(6) Grouting Pipe is inserted to the bottom of miniature steel pipe pile, the cement mortar mixed slowly is injected into miniature steel pipe by slip casting machine
In stake, the ratio of mud of cement mortar is strict controlled in 0.45~0.5, to pay attention to the pressure gauge in Grouting Pipe during slip casting the moment,
Ensure that grouting pressure reaches 0.5MPa, Grouting Pipe wouldn't be pulled out after slip casting, untill cement mortar flows out outside miniature steel pipe pile, pull out
Go out Grouting Pipe, sealed steel pipe end, pressurize 5 minutes, untill treating that cement mortar flows out outside steel pipe again, if once grouting is difficult to completely
Foot set rushing be full of coefficient requirement, it is necessary to repeatedly gap slip casting, until miniature steel pipe pile stake top frost boiling untill, then extract note
Slurry pipe, completes slip casting operation, the ring flange of sheathed wire termination is ensured during slip casting slurries entrance；
(7) temperature self-compensation type fiber Bragg grating strain sensor string, optical fiber grating sensing analyzer and data storage computer are connect
It is logical, the survival rate of detection temperature self-compensation type mini optical fibre grating strain transducer string；
(8) before excavation of foundation pit, the cement mortar in the miniature steel pipe pile after slip casting conserves 28 days or the compression strength of cement mortar
After reach design strength 75%, by temperature self-compensation type fiber Bragg grating strain sensor string, optical fiber grating sensing analyzer and
Data storage computer is connected, and checks whether test device connection is intact, and record temperature self-compensation type fiber grating strain sensor
Device string initial wavelength；
(9) in Excavation Process, temperature self-compensation type is recorded in real time with optical fiber grating sensing analyzer and data storage computer
The wavelength of mini optical fibre grating sensor string, the section to be measured of miniature steel pipe pile can be tried to achieve using formula (1), (2), (3)
Pile body bending stress,
Δεx=Δ λε/Kε (1)
σi=EsΔεx (2)
Mi=σiW (3)
Wherein Δ εxFor the axial strain variable quantity of miniature steel pipe pile；ΔλεCentered on wavelength variable quantity, unit nm；KεFor sensing
Device gage factor；σiFor the bending stress at any test section mini steel-pipe pile axis, its numerical value faces soil equal to foundation ditch
Face and the half of excavation face stress difference, units MPa；EsFor the modulus of elasticity of miniature steel pipe pile, units MPa；MiFor any test
The moment of flexure of section mini steel-pipe pile, unit kNm；W be miniature steel pipe pile bending sections coefficient, unit mm3；For safety
Consider, formula (3) does not consider increase effect of the slip casting to bending rigidity in miniature steel pipe pile in calculated bending moment；If consider
The increase effect of miniature steel pipe pile bending rigidity after slip casting, the rigidity of non-slip casting miniature steel pipe pile can be multiplied by 1.2~1.5 increasing
Big coefficient.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710938330.9A CN107643138A (en) | 2017-09-30 | 2017-09-30 | Miniature steel-pipe pile body stress test device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710938330.9A CN107643138A (en) | 2017-09-30 | 2017-09-30 | Miniature steel-pipe pile body stress test device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN107643138A true CN107643138A (en) | 2018-01-30 |
Family
ID=61111918
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710938330.9A Withdrawn CN107643138A (en) | 2017-09-30 | 2017-09-30 | Miniature steel-pipe pile body stress test device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107643138A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108303199A (en) * | 2018-04-04 | 2018-07-20 | 单华峰 | A kind of new reinforcing steel bar stress meter and its installation method for steel-pipe pile |
| CN109837931A (en) * | 2019-01-28 | 2019-06-04 | 武汉理工大学 | Wisdom prefabricated pile |
| CN110031325A (en) * | 2019-05-28 | 2019-07-19 | 佛山市禅城区建设工程质量安全检测站 | A kind of pile stress test system and method |
| CN112681410A (en) * | 2021-01-21 | 2021-04-20 | 陈丽 | Concrete pipe pile pressure detector and detection method thereof |
| CN113607215A (en) * | 2021-08-04 | 2021-11-05 | 日喀则市交通运输局公路工程项目管理中心 | Remote monitoring method and system for bearing capacity of pile foundation of cast-in-place pile |
| CN115233747A (en) * | 2022-07-13 | 2022-10-25 | 青岛理工大学 | Device and method for testing stress of micro steel pipe pile in miscellaneous filled stratum |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103485373A (en) * | 2013-10-12 | 2014-01-01 | 青岛理工大学 | Method for testing pile body stress of static pressure high-strength prestressed concrete pipe pile |
| CN103512686A (en) * | 2013-10-12 | 2014-01-15 | 青岛理工大学 | Static pressure high-strength prestressed concrete pipe pile body stress testing device |
| CN105672376A (en) * | 2016-04-01 | 2016-06-15 | 青岛理工大学 | Prestressed pipe pile body internal force device implanted with fiber bragg grating sensor |
| CN105780826A (en) * | 2016-04-01 | 2016-07-20 | 青岛理工大学 | In-situ testing method for internal force of pile body of prestressed pipe pile implanted with fiber bragg grating sensor |
| CN106013276A (en) * | 2016-07-04 | 2016-10-12 | 中国电建集团华东勘测设计研究院有限公司 | Stress-strain testing system for large-diameter steel pipe pile of offshore wind turbine and construction method |
-
2017
- 2017-09-30 CN CN201710938330.9A patent/CN107643138A/en not_active Withdrawn
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103485373A (en) * | 2013-10-12 | 2014-01-01 | 青岛理工大学 | Method for testing pile body stress of static pressure high-strength prestressed concrete pipe pile |
| CN103512686A (en) * | 2013-10-12 | 2014-01-15 | 青岛理工大学 | Static pressure high-strength prestressed concrete pipe pile body stress testing device |
| CN105672376A (en) * | 2016-04-01 | 2016-06-15 | 青岛理工大学 | Prestressed pipe pile body internal force device implanted with fiber bragg grating sensor |
| CN105780826A (en) * | 2016-04-01 | 2016-07-20 | 青岛理工大学 | In-situ testing method for internal force of pile body of prestressed pipe pile implanted with fiber bragg grating sensor |
| CN106013276A (en) * | 2016-07-04 | 2016-10-12 | 中国电建集团华东勘测设计研究院有限公司 | Stress-strain testing system for large-diameter steel pipe pile of offshore wind turbine and construction method |
Non-Patent Citations (2)
| Title |
|---|
| 周小龙: "青岛地铁土岩结合基坑支护中微型钢管桩的试验研究", 《青岛理工大学硕士学位论文》 * |
| 石振明 等: "光纤检测技术在海上钢管桩试桩中的应用", 《工程地质学报》 * |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108303199A (en) * | 2018-04-04 | 2018-07-20 | 单华峰 | A kind of new reinforcing steel bar stress meter and its installation method for steel-pipe pile |
| CN108303199B (en) * | 2018-04-04 | 2023-12-15 | 单华峰 | Novel steel bar stress meter for steel pipe pile and installation method thereof |
| CN109837931A (en) * | 2019-01-28 | 2019-06-04 | 武汉理工大学 | Wisdom prefabricated pile |
| CN110031325A (en) * | 2019-05-28 | 2019-07-19 | 佛山市禅城区建设工程质量安全检测站 | A kind of pile stress test system and method |
| CN112681410A (en) * | 2021-01-21 | 2021-04-20 | 陈丽 | Concrete pipe pile pressure detector and detection method thereof |
| CN113607215A (en) * | 2021-08-04 | 2021-11-05 | 日喀则市交通运输局公路工程项目管理中心 | Remote monitoring method and system for bearing capacity of pile foundation of cast-in-place pile |
| CN115233747A (en) * | 2022-07-13 | 2022-10-25 | 青岛理工大学 | Device and method for testing stress of micro steel pipe pile in miscellaneous filled stratum |
| CN115233747B (en) * | 2022-07-13 | 2024-02-27 | 青岛理工大学 | Device and method for testing stress of miniature steel pipe pile in miscellaneous fill stratum |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107643138A (en) | Miniature steel-pipe pile body stress test device | |
| CN107643137A (en) | Method for testing pile body stress of miniature steel pipe pile | |
| Hong et al. | Recent progress of using Brillouin distributed fiber optic sensors for geotechnical health monitoring | |
| Wu et al. | Optical fiber-based sensing, measuring, and implementation methods for slope deformation monitoring: A review | |
| Zhu et al. | An optical fibre monitoring system for evaluating the performance of a soil nailed slope | |
| CN102221332A (en) | Fiber grating multi-point sensing device for unconsolidated strata as well as monitoring system and method | |
| CN105318824B (en) | A kind of method that wall rock loosening ring is measured based on distributed resistance foil gauge | |
| CN105973285A (en) | Multifunctional intelligent anchor pole and installation arrangement method thereof | |
| CN105971647B (en) | A kind of multi-functional FRP intelligent anchor rods of single-point temperature compensation and preparation method thereof | |
| CN207215329U (en) | Miniature steel-pipe pile body stress test device | |
| CN103512686A (en) | Static pressure high-strength prestressed concrete pipe pile body stress testing device | |
| CN106225818A (en) | A kind of single-point temperature compensation multifunctional intellectual anchor pole and installation distribution method thereof | |
| CN108918012A (en) | One kind being used for Shield-bored tunnels country rock Disturbance stress monitoring method | |
| CN107529615A (en) | A kind of three-dimensional turbulence stress test method of face surrounding rock | |
| CN107402087A (en) | A kind of monitoring device and monitoring system of country rock three-dimensional turbulence stress field | |
| CN107356356A (en) | The fiber grating surrouding rock stress monitoring device and monitoring system of a kind of high-survival rate | |
| CN207074097U (en) | A kind of monitoring device and monitoring system of country rock three-dimensional turbulence stress field | |
| CN102278948A (en) | Compound optical fiber sensing monitoring system and method based on optical fiber compound sensing module | |
| CN104897321B (en) | Wall shearing stress method of testing in a kind of pre-formed members concrete tubular pile pile body | |
| CN207228185U (en) | Open-end PHC tubular pile end resistance testing device | |
| CN201561828U (en) | Fiber grating geological disaster monitor | |
| CN107860496A (en) | Method for testing shear stress on surface of full-length bonded steel bar anchor rod body | |
| CN204988572U (en) | Skin friction testing arrangement in prefabricated opening concrete pipe pile pile body | |
| Yang et al. | Sensor monitoring of a newly designed foundation pit supporting structure | |
| CN207248395U (en) | The fiber grating surrouding rock stress monitoring device and monitoring system of a kind of long term monitoring |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WW01 | Invention patent application withdrawn after publication |
Application publication date: 20180130 |
|
| WW01 | Invention patent application withdrawn after publication |